Method and apparatus for refrigeration utilizing sterling cycle type of operation



April 4, 1967 w. E. GIFFORD 3,312,072

METHOD AND APPARATUS FOR REFRIGERATION UTILIZING STERLING CYCLE TYPE OF OPERATION 2 Sheets-Sheet l Filed June 11, 1965 mam/Win42"! 4 a nru nm 7024's 7 LOW rea ms/247v:

k'fk/aaurlanl April 4, 1967 Filed June 11, 1965 w. E. GIFFORD' 3,312,072

METHOD AND APPARATUS FOR REFRIGERATION UTILIZING STERLING CYCLE TYPE OF OPERATION 2 Sheets-Sheei 2 ;9' a j I l I I t I I I 22 i i i I United States Patent Ofilice 3,31Z,72 Patented Apr. 4, 1967 3,312,072 METHOD AND APPARATUS FOR REFRIGERA- TION UTILIZING STERLING CYCLE TYPE OF OPERATIGN William E. Gifford, 829 Ostrom Ave, Syracuse, N.Y. 1321i? Filed June 11, 1965, Ser. No. 463,173 4 Claims. (Cl. 626) This invention relates to an improved method and apparatus for producing refrigeration and, more particularly, to a method based on a closed gas cycle of the Sterling gas cycle type.

It is a chief object of the invention to provide an improved method and apparatus for producing refrigeration of the class indicated.

The nature of the invention and its other objects and novel features will be more fully understood and appreciated from the following description of preferred embodiments of the invention selected for purposes of illustration and shown in the accompanying drawings, in which:

. FIGURE 1 is an elevational view partly in cross section of the refrigerating apparatus of the invention; and

FIGURE 2 is another elevational view partly in cross section illustrating another form of refrigeration apparatus.

In the structure shown in the drawings, numeral 2 denotes a cylinder in which is mounted a displacer 4 which defines three volumes 3, 5 and 7. At one side of cylinder 2 is a cylinder body 6 in which is a displacer 8 defining volumes 9-11. Volume 9 connects with volume 5 through a passageway 10.

A first rotary valve 12 has two ports 14 and 15. The valve may be driven by an electric motor or other suitable means. Port 16 is connected through conduit 18 to volume 3. Likewise, port 16 is connected through a conduit 20 and regenerator 22 to volume 11. Compressed gas, as helium, may be supplied from compressor 24 through ports 14 or 16 to volumes 3 and 11, depending on Whether high pressure slots 26 or low pressure slots 25 in valve 12 is in register with ports 14 and 16. Low pressure may be from 15 to 200 pounds per square inch and suitable high pressures may run from 200 to 500 pounds per square inch.

Volume 5 is interconnected with volume 7 through heat exchanger 32 and thermal regenerator member 34 so that pressure in volumes 5, 9 and 7 are always very nearly the same.

In operation a starting point may be with the low pressure slot registering with ports 14 and 16 and displacer 4 in an uppermost position, and displacer 8 in a lowermost position so that volumes 7 and 11 are at low pressure and displacer 4 is in its highest position (FIG- URE l).

The rotary valve moves bringing high pressure port 26 into register with port 14 thus increasing pressure in volume 3 and driving displacer 4 to its lowest position in the cylinder 2. Then the high pressure slot 26 is brought into register with port 16 thereby increasing the pressure in volume 11.

This results in displacer 8 moving upwards compressing gas in volumes 9 and 5. When pressure increases to high pressure value or level, the low pressure slot comes into register with port 14 letting pressure down in volume 3 unbalancing the pressure on displacer 4 so that the displacer 4 moves to its topmost position displacing gas from volumes 5 and 9 through the heat exchanger 32 where heat of compression is removed and then through thermal regenerator 34 where gas is cooled by storing refrigeration in the matrix of the regenerator.

With further rotation of the valve the low pressure slot 25 is placed in register with port 16 thus allowing the high pressure gas in volume 11 to exhaust causing the displacer 4 to move down and thus allowing gas to expand out of volume 7 into volumes 9 and 5. This expansion results in the expansion of some gas in volume 7, and some other gas in volume 11, resulting in cooling to produce refrigeration in volumes 11 and 7 at different low temperatures. Further rotation of the valve repeats the cycle described.

As a result of this cycle the gas confined in volumes 9, 5 and 7 proceeds through a Sterling or Brayton cycle wherein the gas is compressed at room temperature in volumes 5 and 9 and expanded at a low temperature in volume 7 yielding useful low temperature refrigeration. In addition refrigeration is achieved in volume 11 at a different low temperature somewhat less efficiently than that of the Sterling or Brayton cycles.

It is pointed out that the operation described is achieved by a simple arrangement of parts as described. In the operation of the device, the additional amount of refrigeration is generated in volume 11 which may be used to cool the cylinder 2. Advantages of the single valve arrangement described are that the gas used in the refrigeration end is in a separate elosed-ofl? system where it resists becoming contaminated. from contact with other parts of the apparatus.

Another arrangement of refrigeration is to use an additional valve V2 as shown in FIGURE 1 which supplies additional high pressure gas through conduit 19 to volume 5 and volume 7 when the gas from valve 1 is being displaced from volume 5 to volume 7 so that pressure will not decrease when gas is transferred to the colder region 7 or increase in reverse. Valve V2 has high and low pressure slots 27 and 29 which in proper register to port 31 gives this specified function. Details of the valves V1 and V2 may be of the type shown in US. Patent No. 3,119,237.

The invention may be embodied in two-stage system as shown in FIGURE 2 wherein the same but primed numerals refer to parts similar to those in FIGURE 1 and further including the additional cylinder 2', displacer 4", and displacer 34'. The additional cylinder and displacer define three new volumes 3" connected with 3', 5" connected to 5' and 9', and '7" interconnected through additional regeneration 34" with volume 7 Displacer 4" moves in unison with displacer 4' so that volumes 3", 5" and 7" serve a similar function to 3', 5' and 7. However, the refrigeration achieved in volume 7" will be at a different lower temperature than that in 7'.

While I have shown and described a preferred form of the invention, changes and modifications may be re sorted to within the scope of the appended claims.

I claim:

1. In a method of producing refrigeration in which gas from a high pressure supply source is supplied through a valve means to a confined space whose volume is separated into five lesser volumes, three of which are connected together through heat exchanger and regenerator and the remaining two of which are unconnected, by walls movable under pressure, two of which volumes are con.- nected to one another for the flow of gas therebetween, and said valve means comprising a multipassage inlet and outlet valve for controlling flow of fluid into the two unconnected volumes, the steps which include supplying high pressure gas to one of the unconnected volumes thus causing one of the movable walls to move downwardly and displacing low pressure gas from one of the other two connected volumes, then introducing high pressure gas to the second unconnected volume through a thermal regenerator thereby causing the other movable wall to move and compress gas in two of the connected volumes, then moving the valve to reduce pressure in the first unconnected volume so that the first movable Wall can move upwardly displacing gas from the two connected volumes to the third connected volume through a heat sink heat exchanger and thermal regenerator, then reducing the pressure in the second unconnected volume and causing the second movable wall to move and allow compressed gas to expand and produce refrigeration.

2. A method for producing refrigeration according to claim 1 in which the gas in the three connected volumes passes through a cycle generally resembling a Sterling cycle.

3. A refrigeration apparatus comprising a first enclosure having a displacer movable therein to vary an upper volume, an intermediate volume and a lower volume, gas conduit means connecting the lower volume and the intermediate volume and said conduit means having a heat exchanger and a regenerator member located therein, a second enclosure mounted adjacent the first enclosure and a second displacer movable in the said second enclosure member to vary an upper volume and a lower volume, means for supplying a compressed gas, a motor driven rotary valve member rotatable to regulate flow of compressed gas from the supply means, said valve being formed with a high pressure gas passageway and a low pressure gas passageway, said valve being further formed with a port for communicating with the high pressure passageway in one position of rotation of the valve memher and a second port for communicating with the low pressure pasageway in another position of rotation of the valve member, a gas conduit connecting the said valve with the said lower volume of the second enclosure mem ber, an additional gas conduit connecting the valve with the upper volume of the said first enclosure and said upper volume of the said second enclosure being connected to the intermediate volume of the said first enclosure by means of a passageway and said displacer members being movable in response to flow of compressed gas through the valve and conduit members to provide refrigeration at the surface adjacent the lower volume of the said second enclosure and also-the bottom surface of the lower volume in the said first enclosure.

4. A structure according to claim 3 in which a second valve member is employed and an additional enclosure member with upper, intermediate and lower volumes is connected thereto.

References Cited by the Examiner UNITED STATES PATENTS 3,115,016 12/1963 Hogan 62-6 3,138,004 6/1964 Gifiiord 62-6 3,188,819 6/1965 Hogan 62-6 3,188,821 6/1965 Chellis 626 WILLIAM J. WYE, Primary Examiner. 

1. IN A METHOD OF PRODUCING REFRIGERATION IN WHICH GAS FROM A HIGH PRESSURE SUPPLY SOURCE IS SUPPLIED THROUGH A VALVE MEANS TO A CONFINED SPACE WHOSE VOLUME IS SEPARATED INTO FIVE LESSER VOLUMES, THREE OF WHICH ARE CONNECTED TOGETHER THROUGH HEAT EXCHANGER AND REGENERATOR AND THE REMAINING TWO OF WHICH ARE UNCONNECTED, BY WALLS MOVABLE UNDER PRESSURE, TWO OF WHICH ARE UNCONNECTED, BY WALLS NECTED TO ONE ANOTHER FOR THE FLOW OF GAS THEREBETWEEN, AND SAID VALVE MEANS COMPRISING A MULTIPASSAGE INLET AND OUTLET VALVE FOR CONTROLLING FLOW OF FLUID INTO THE TWO UNCONNECTED VOLUMES, THE STEPS WHICH INCLUDE SUPPLYING HIGH PRESSURE GAS TO ONE OF THE UNCONNECTED VOLUMES THUS CAUSING ONE OF THE MOVABLE WALLS TO MOVE DOWNWARDLY AND DISPLACING LOW PRESSURE GAS FROM ONE OF THE OTHER TWO CONNECTED VOLUMES, THEN INTRODUCING HIGH PRESSURE GAS TO THE SECOND UNCONNECTED VOLUME THROUGH A THERMAL REGENERATOR THEREBY CAUSING THE OTHER MOVABLE WALL TO MOVE AND COMPRESS GAS IN TWO OF THE CONNECTED VOLUMES, THEN MOVING THE VALVE TO REDUCE PRESSURE IN THE FIRST UNCONNECTED VOLUME SO THAT THE FIRST MOVABLE WALL CAN MOVE UPWARDLY DISPLACING GAS FROM THE TWO CONNECTED VOLUMES TO THE THIRD CONNECTED VOLUME THROUGH A HEAT SINK HEAT EXCHANGER AND THERMAL REGENERATOR, THEN REDUCING THE 